1. Technical Field
The present invention relates to magnetoresistive transducers. More particularly, the present invention relates to an improved magnetoresistive read transducer having a transverse easy axis for biasing and domain stabilization.
2. Description of the Prior Art
Continuing advances in magnetic media technology allow increasing data storage densities. One active area of development is that of reading transducers. As such transducers are made smaller, data densities are increased. Magnetoresistive (MR) thin film technology has provided a particularly promising area of inquiry with regard to producing smaller reading transducers. In such technology, conductive thin films are formed on a substrate using techniques analogous to those of the semiconductor arts.
The present state of the art teaches the use of magnetoresistive elements having an easy axis in-plane and along the length of the MR elements. In this configuration, magnetic poles exist at the ends of the stripes and thus result in instabilities, unwanted domain states, and unpredictable response curves. This arrangement is currently in use for the three basic geometries which employ MR technology: single layer structures, soft adjacent layer (SAL) structures where an additional magnetic film is provided to help in biasing the transducer, and dual stripe structures in which both films are magnetoresistive.
Magnetoresistive memory elements have been discussed by Pohm and Comstock, IEEE Trans. Mag. 26, 2529 (1990), which use transverse anisotropy in coupled magnetic films for storing digital information, but not for sensing magnetic fields. However, there is yet to be taught any technique for applying this approach to magnetoresistive transducers, nor is there any recognition that such teachings would be useful in the transducer arts.